Quick Revision

GK One-Line Question & Answer

15541+ short questions with short answers, covering every category and sub-category on the site — no long articles to scroll through. Good for a fast recap before an exam, or a few minutes of daily practice.

Looking for exam process/strategy questions instead? Try the Exam Preparation FAQ →

DBMS → Data Models 3

Which of the following is a legal expression in SQL?
SELECT NAME FROM EMPLOYEE;
click to copy
Which of the following is the formal process for deciding which attributes should be grouped together in a relation?
Normalization
click to copy
A 3 NF relation is split into 4 NF
by splitting into relations which do not have more than one independent multi valued dependency
click to copy

DBMS → ER Model 3

If every non-key attribute is functionally dependent on the primary key, then the relation will be in:
Third normal form
click to copy
Who developed normalization process?
E.F. Codd
click to copy
Using the SQL GROUP BY phrase with a SELECT statement can help detect which of the following problems?
The inconsistent values problem
click to copy

DBMS → Relational Model 3

Given the functional dependencies X →W; X→Y; Y→Z and Z→PQ Which of the following doesn’t hold well?
W→Z
click to copy
Who developed the BCNF?
Boyce and Codd
click to copy
What SQL command will allow you to change the table STUDENT to add the constraint named GradeCheck that states that the values of the Grade column must be greater than 0?
ALTER TABLE STUDENT ADD CONSTRAINT GradeCheck CHECK (Grade > 0);
click to copy

DBMS → Normalization 3

Relations produced from an E-R model will always be in
Third normal form
click to copy
What is the expansion of BCNF?
Boyce-Codd Normal Form
click to copy
The NOT EXISTS keyword will be true if:
all rows in the subquery fail the condition.
click to copy

DBMS → Functional Dependency 2

Third normal form is inadequate in situation where the relation
Has multiple candidate keys
click to copy
Which of the following is the result of a transitive dependency?
All of the above
click to copy

DBMS → SQL Basics 2

If a relation scheme is in BCNF, then it is also in
Third normal form
click to copy
How many inference rules are there for functional dependencies?
6
click to copy

DBMS → DDL Commands 2

A primary key when combined with a foreign key create
Parent child relationship between the tables that connect them.
click to copy
Which property ensures that each functional dependency is represented in some individual relations resulting after decomposition?
Dependency preservation property
click to copy

DBMS → DML Commands 2

The set of permitted value for each attribute is called its
Domain
click to copy
Every relation in BCNF is also in
3NF
click to copy

DBMS → Joins 2

The airline reservation system, the enables are date, flight number, place of departure, destination, type of plane & seats available. The primary key is
Flight number+ date
click to copy
A table that contains one or more repeating groups is in which normal form?
Unnormalized Form
click to copy

DBMS → Views 2

A functional dependency of the form X→Y is trivial if
YC= X
click to copy
A relation is said to be in 3 NF if (i) it is in 2 NF (ii) non-key attributes are independent of one another (iii) key attribute is not dependent on part of a composite key (iv) has no multi-valued dependency
i and ii
click to copy

DBMS → Indexes 2

The concept of locking can be used to solve the problem of
Lost update
click to copy
Given the following relation it is not 3 NF because Student (roll no, name, course no, course max. marks, year of study, address)
non-key attributes course no and course max. marks are functionally dependent
click to copy

DBMS → Transactions 2

A schedule S of n transactions is serializable if it is equivalent to some
Serial schedule of the same n transactions.
click to copy
Given the following relation Student (roll no, name, course no, course max. marks, year of study, address) The corresponding 3 NF relations are
student ( roll no, name, year of study, address) student (roll no, course no) course (course no, course max. marks)
click to copy

DBMS → Concurrency Control 2

In two-phase locking protocol.
All locking operations precede the first unlock operation.
click to copy
BoyeCodd Normal Form (BCNF) is needed when
there are two or more possible composite overlapping keys and one attributeof a composite key is dependent on an attribute of another composite key
click to copy

DBMS → Deadlock 2

Transaction timestamp is:
Unique identifier assigned to each transaction.
click to copy
A relation is said to be in BCNF when
it has no overlapping composite keys which have related attributes
click to copy

DBMS → Database Security 2

The granularity of a database item can be chosen to be
All of the above.
click to copy
A 3 NF relation is converted to BCNF by
dependent attributes of overlapping composite keys are put in a separateRelation
click to copy

DBMS → PL/SQL 2

If the complete execution of the transaction(s) takes the database from one consistent state to the other then that property of transaction is called:
Consistency preservation
click to copy
BCNF is needed because
when there is dependent attributes in two possible composite keys one of the attributes is unnecessarily duplicated in the tuples
click to copy

DBMS → Introduction to DBMS 2

Which of the following is not the state that the transaction undergoes?
Non active
click to copy
Given the relation Supplier(s_id, p_order, s_name, qty) Given that there is a unique s_name for each s_id and that s_id, p_order is a composite key, find the correct statement among the following: i. this relation is a BCNF ii. this is 3 NF relation iii. this is a 2 NF relation iv. this is a 1 NF relation
i and iii
click to copy

DBMS → Database Architecture 2

Timestamp can be generated by:
Both (a) and (b)
click to copy
A relation project guidance Project Guidance(professor, project, student no. st-name, dept) A professor can give many projects to many students A project will have many students A project may be guided by many professors The 4 NF relation corresponding to this are
Prof_stud (professor, student no) Proj_stud (project, student no)
click to copy